Pain is an unpleasant sensory and emotional experience caused by actual or potential tissue damage. It serves a protective function by warning us of damage. Pain is transmitted through specialized pain pathways and is classified based on duration, location, and source. There are different types of pain receptors that detect various painful stimuli and transmit signals through different nerve fiber types to the central nervous system where pain is perceived.
Pain is one of the most commonly experienced symptom . It is often spoken of as a protective mechanism since it is usually manifested when an environmental change occurs that causes injury to responsive tissue
Pain is one of the most commonly experienced symptom . It is often spoken of as a protective mechanism since it is usually manifested when an environmental change occurs that causes injury to responsive tissue
Pain is one of the most commonly experienced symptom . It is often spoken of as a protective mechanism since it is usually manifested when an environmental change occurs that causes injury to responsive tissue
Pain is one of the most commonly experienced symptom . It is often spoken of as a protective mechanism since it is usually manifested when an environmental change occurs that causes injury to responsive tissue
Innervation of the face
The nervvous system
Nerve transmission
Definition of Pain
Pain Receptors
Pain nerve fibers
Reaction to pain
Pain Pathway
Control of Pain
Mode of action of local anesthesia
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Innervation of the face
The nervvous system
Nerve transmission
Definition of Pain
Pain Receptors
Pain nerve fibers
Reaction to pain
Pain Pathway
Control of Pain
Mode of action of local anesthesia
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
pain. Medical Surgical Nursing ......pptxPatelVedanti
Pain is a complex, multidimensional phenomenon. Everyone has experienced some types or degrees of pain. Pain is the most common reason for physician and also common problems faced by nurses when they are dealing with the patients.
The word pain is derived from the Latin word ‘Poena’ which means punishment. It is a major symptom in many medical conditions, and can significantly interfere with a person's quality of life and general functioning.
Pain motivates us to withdraw from potentially damaging situations, protect a damaged body part while it heals, and avoid those situations in the future.
Most pain resolves promptly once the painful stimulus is removed and the body has healed, but sometimes pain persists despite removal of the stimulus and apparent healing of the body; and sometimes pain arises in the absence of any detectable stimulus, damage or disease.
The International Association for the Study of Pain's widely used definition states:
"Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage".
The processes in the body that are involved in the perception of pain are called "nociception."
Mount castle defined pain as “that sensory experiences evoked by stimuli that injure or threaten to destroy tissue, defined introspectively by every man as that which hurts”.
The International Association for the Study of Pain (IASP) classification system describes pain according to five categories:
Duration And Severity,
Anatomical Location,
Body System Involved,
Cause, And
Temporal Characteristics (Intermittent, Constant, Etc)
Acute pain lasts a short time, or is expected to be over soon. The time frame may be as brief as seconds or as long as weeks.
Chronic pain may be defined as pain that lasts beyond the healing of an injury, continues for a period of several months or longer, or occurs frequently for at least months and is more difficult to manage.eg-rheumatoid arthritis
Cutaneous or superficial pain- it is directly precised &readily localized i.e. patient can indicate exactly where it hurt.
Referred pain- pain felt at a site distinct from site of pain. eg-cardiac pain is present in the heart, but felt in the left arm
Intractable pain- persistent, severe pain that cannot be effectively controlled by the usual medication is referred to as “Intractable pain”.
Localized pain- Localized pain arises directly from the site of the disturbance.
Differentiation of neurolapatic pain- severs pain caused by nervous system damage, when the flow of afferent nerve impulse has been partially or completely interrupted. eg accident.
Pain of muscular or bonny origin- the muscular ischemia of intermittent claudication(a in commonly in the legs or arms that comes on with walking or using the arms.) & occlusion vascular induce pain in the extrimities. eg joint pain
In this presentation I have tried to explain in brief about pain management, different types of pain, its diagnostic criteria, its physiology, and its treatment approaches both pharmacological and non pharmacological
Pain is the common symptom in many chronic conditions such as cancers, neuropathies, and chronic disease. It is also experienced in trauma varying from mild to severe based on the location and degree of trauma. This presentation is a brief outline on types of pain, classification of pain, pain pathways and management of pain
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
MANAGEMENT OF ATRIOVENTRICULAR CONDUCTION BLOCK.pdfJim Jacob Roy
Cardiac conduction defects can occur due to various causes.
Atrioventricular conduction blocks ( AV blocks ) are classified into 3 types.
This document describes the acute management of AV block.
The prostate is an exocrine gland of the male mammalian reproductive system
It is a walnut-sized gland that forms part of the male reproductive system and is located in front of the rectum and just below the urinary bladder
Function is to store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid that along with the spermatozoa, constitutes semen
A healthy human prostate measures (4cm-vertical, by 3cm-horizontal, 2cm ant-post ).
It surrounds the urethra just below the urinary bladder. It has anterior, median, posterior and two lateral lobes
It’s work is regulated by androgens which are responsible for male sex characteristics
Generalised disease of the prostate due to hormonal derangement which leads to non malignant enlargement of the gland (increase in the number of epithelial cells and stromal tissue)to cause compression of the urethra leading to symptoms (LUTS
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
1. Pain and Pain Pathways
Anjali Savita
MDS I
Dept of Conservative Dentistry and
Endodontics
2. “I don’t accept the maxim ‘there is no gain
without pain’, physical or emotional. I believe it
is possible to develop and grow with joy rather
than grief; however when pain comes my way, I
try to get the most growth out of it”
- Alexa Mclaughlin
4. Introduction
Pain is the commonest symptom which physician are
called upon to treat.
Pain is an intensely subjective experience, and is
therefore difficult to describe.
Physiology of pain has taught us a lot about neural
function in general.
It has two universal features. First, its an unpleasant
experience. Second, it is evoked by a stimulus which is
actually or potentially damaging to living tissue.
5. That is why, although it is unpleasant, pain serves a
protective function by making us aware of actual or
impeding damage to the body.
Like all sensory experiences, pain has two
components, the first component is awareness of
painful stimulus and second one is emotional impact(or
effect) evoked by experience.
While the awareness is localized to the area
stimulated, experience involve the whole being.
That is why when a finger is hurt, the whole person
suffers.
6. Definition of Pain
Pain is “an unpleasant sensory and emotional experience
associated with actual or potential tissue damage, or described
in terms of such damage”.
- International association for the study of Pain.
“An unpleasant emotional experience usually initiated by
noxious stimulus and transmitted over a specialized neural
network to the CNS where it is interpreted such as.”
- Monheim’s textbook of local anaesthesia
7. History
Derived from Latin word “poena” meaning punishment from
God.
Homer thought pain is due to arrows shot by God.
Aristotle who was first to distinguish five physical senses
considered pain to “ the passion of the soul” that somehow
resulted from intensification of other sensory experience.
Plato contented, pain and pleasure arose from within the
body.
Bible makes reference to pain not only in relationship to
injury and illness but also an anguish of the soul.
8. Incidence of Pain
According to Cohen- it was found that 21.8% of adult in the united states
experiences orofacial pain symptoms within 6 months of study.
The most common pain was toothache, which was estimated to have
occurred in 12.3% of the population.
Dental pain is highly prevalent among children, the association being most
apparent in lower socioeconomic groups with reduced access to care.
The prevalence of dental pain was 35% among all pain.
Dental pain has been associated with many factors, such as low
socioeconomic status, high levels of dental caries and restricted access to
dental services.
10. Characteristic of Pain
Threshold and Intensity
If the intensity of the stimulus is below the threshold(sub
threshold) pain is not felt. As the intensity increases more
and more, pain is felt more and more according to Weber-
Fechner’s Law.
As per this law magnitude of sensation felt is directly
proportional to log of intensity of stimulus
11. Adaptation
Pain receptors show no adaptation, so the pain continues as
long as receptors are stimulated.
Localization of pain
Pain sensation is somewhat poorly localized, however
superficial pain is comparatively better localized than deep pain.
Influence of the rate of damage on intensity of pain
If rate of damage(tissue injury) is high, intensity of pain is also
high.
13. ACUTE PAIN
Acute has a sudden onset, usually subsides quickly and is characterized by sharp,
localized sensations with an identifiable cause.
Lasts > 30 days and occurs after muscle strains and tissue injury such as trauma or
surgery.
A poorly treated pain can cause psychological stress and compromise the immune
system due to the release of endogenous corticosteroids
Acute pain is usually characterized by increased autonomic nervous system activity
resulting in psychological symptoms such as anxiety
Tachypnoea
Tachycardia with hypertension
Pallor
Diaphoresis
Pupil dilation
14. VISCERAL PAIN
Visceral pain is a type of nociceptive pain that comes from the
internal organs.
Unlike somatic pain it is harder to pinpoint, described as general
aching or squeezing pain
It is caused by the activation of pain receptors in the chest,
abdomen, or pelvic areas.
In cancer patients pain is caused by tumor infiltration,
constipation, radiation & chemotherapy.
15. SUPERFICIAL PAIN
It is also known as
cutaneous pain.
It arises from superficial
structures such as skin &
subcutaneous tissues.
It is a sharp, bright pain
with a burning quality and
may be abrupt or slow in
onset.
DEEP SOMATIC PAIN
It originates in deep body
structures such as
periosteum, muscles,
tendons, joints & blood
vessels
Strong pressure, ischemia,
tissue damage act as stimuli
for brain damage
Radiation of pain from
original site of injury occur.
16. CHRONIC PAIN
Chronic pain is defined as pain lasting longer than 3 to 6
months.
It begins when pain persists after the initial injury has
healed.
It is persistent or episodic pain of duration or intensity
that adversely affects the function and well being of the
patient.
It may be nociceptive, inflammatory, neuropathic or
functional in origin.
17. It occurs in 60-90 % of patients
with cancer.
Pain can be related to the tumor
or cancer therapy or may be
idiosyncratic.
Pain may also be found at the
metastasized regions and
treatment interventions may
activate peripheral nociceptors.
Pain can be somatic/visceral
CHRONIC NONCANCER PAIN
Pain may last for many years
and is considered progressive in
nature.
May be nociceptive, neuropathic
or mixed in nature.
CHRONIC MALIGNANT PAIN
18. NEUROPTHIC PAIN
Neuropathic pain is a result of an injury or malfunction of the
nervous system.
It is described as
Aching
Throbbing
Burning
Shooting
Tenderness/ sensitivity of skin
20. MUSCULOSKELETAL PAIN
This a type of chronic non cancer pain occurring due to
musculoskeletal disorders such as
Rheumatoid arthritis
Osteoarthritis
Fibromyalgia
Peripheral neuropathies
21. BASED ON TRANSMISSION
FAST PAIN
Felt about 0.1 sec after a
painful stimulus is applied.
It is described as sharp pain,
pricking pain, acute & electric
pain
Fast sharp pain is not felt in
most deeper tissues of the
body.
Due to activation of Aδ fibres
SLOW PAIN
Usually begins after 1 sec or
more and may range from
seconds to minutes.
Described as slow, burning,
aching, throbbing, nauseous
pain and chronic pain
Associated with tissue
destruction.
Due to activation of C fibres
22. OTHER TYPES OF PAIN
REFERRED PAIN
Pain that originate due to
irritation of a visceral organ and
felt not in organ but in some other
somatic structure as well which
has innervated by the same neural
segment.
Usually applies to pain that
originates from the viscera
E.g. The pain associated with MI
commonly is referred to the left
shoulder arm, neck & chest.
BREAKTHROUGH PAIN
Pain is intermittent, transitory.
Usually lasts from minutes to
hours and can interfere with
functioning.
E.g. Neuropathic pain, Lower
back pain
23.
24. Practical clinical classification of cranio facial pain
General Classification Origin of Pain Quality of Pain
Extra cranial Structure Craniofacial region varies
Referred pain from remote
pathologic sites
Distant organs and
structures
Aching and pressing
Intracranial pathosis Brain and related
structures
Varies
varies
Neurovascular Blood vessels Throbbing, Pulsing,
Pounding
25. General Classification Origin of Pain Quality of Pain
Neuropathic Sensory nervous
system
Shooting, sharp,
burning pain
Causalgic Sympathatic nervous
system
Burning
Muscular Muscles Deep aching, tight
27. AXIS II (psychologic conditions)
Mood disorders
Anxiety disorders
Somatoform disorders
Other conditions
• Psychologic factors affecting a medical condition
28. Pain Receptors
NOCICEPTORS or PAIN RECEPTORS are sensory receptors that
are activated by noxious insults to peripheral tissues.
The receptive endings of the peripheral pain fibres are free
nerve endings.
These receptive endings are widely distributed in the
Skin
Dental pulp
Periosteum
Meninges
29.
30.
31. SILENT
NOCICEPTORS
These receptors
activated at the
time of
inflammation
only.
Upto 40% of C
fibers and 30% of
Aδ fibers are
silent
nociceptors.
UNIMODAL
NOCICEPTOR
S
These
receptors
respond
exclusively to
one modality
i.e. either
noxious
chemical or
heat stimuli.
POLYMODAL
NOCICEPTORS
These receptors
are sensitive to
several varieties
of noxious stimuli
These do not have
a specialized and
simple nerve
endings in the
periphery.
32. NERVE FIBRES INVOLVED IN PAIN TRANSMISSION
A FIBRES
A – BETA
FIBRES
Large
Myelinated
Fast
conducting
Low
stimulation
threshold
Respond to
light touch
C FIBRES
Small & unmyelinated
Very slow conducting
Respond to all types
of noxious stimuli
Transmit prolonged
dull pain
Require high intensity
stimuli to trigger a
response
A – DELTA
FIBRES
Small
Lightly
Myelinated
Slow
conducting
Respond to
heat, pressure,
cooling &
chemicals
Sharp sensation
of pain
33.
34. NEURO TRANSMITTER S INVOLVED IN PAIN
ACTIVATION OF NOCICEPTORS BY INTERACTING WITH OTHER
CHEMICAL MEDIATORS
PGI2
LTs
SUBSTANCES EXITING NCs
HISTAMINE POTASSIUM
ATP
STIMULATION OF
NOCICEPTORS BRADYKININ
DISCHARGE OF PAIN
RELEASING SUBSTANCES
BY NOCICEPTORS
SUBSTANCE – P
GLUTAMATE
SENSITIZATION OF
NOCICEPTORS
PGE2
PGI2
35. PATHWAYS OF PAIN SENSATION
The pathways of pain sensation are as follows
Pathway from skin & deeper tissues
Pathway from face – pain sensation is carried by trigeminal nerve
Pathway from viscera – pain sensation from thoracic &
abdominal viscera are transmitted by sympathetic nerves & from
oesophagus, trachea & pharynx by glossopharyngeal nerves
Pathway from pelvic region – conveyed by sacral
parasympathetic nerves
36. PATHWAY FROM SKIN & DEEPER TISSUES
FIRST
FIRST ORDER
NEURONS
These are the cells in the posterior nerve root ganglia, receive impulses from pain receptors through dendrites
These impulses are transmitted through the axons to spinal cord
Impulses are transmitted by Aδ fibre or C fibres
SECOND ORDER
NEURONS
The neurons of marginal nucleus & substantia gelatinosa form the II order neurons
Fibres from these neurons ascend in the form of the lateral spinothalamic tract
Fibres of fast pain arise from neurons of the marginal nucleus
The fibres of slow pain arise from neurons of substantia gelatinosa
THIRD ORDER
NEURONS
The neurons of pain pathway are the neurons in Thalamic nucleus, reticular formation, tectum, gray matter
around the aqueduct of sylvius
Axons from these neurons reach the sensory area of cerebral cortex or hypothalamus
39. Pain pathway of Maxillofacial region
5TH cranial nerve or trigeminal nerve is the principle
sensory nerve of head region.
Any stimulation in the area of trigeminal nerve is first
received by both myelinated and unmyelinated fibers,
and conducted as an impulse along afferent fibers of
ophthalmic, maxillary and mandibular branches into
semilunar and gasserian ganglion.
Pain impulse descend from the pons by spinal tract
fibers of trigeminal nerve through the medulla
40.
41. MECHANISMS OF PAIN
Pain sensation involves a series of complex interactions
between peripheral nerves & CNS.
Pain sensation is modulated by excitatory and
inhibitory NTs released in response to stimuli.
Sensation of pain is composed of 4 basic processes
Transduction
Transmission
Modulation
Perception
42. TRANSDUCTION
Activation of nociceptor
Intense thermal and mechanical stimuli, noxious chemicals,
noxious cold
Stimulation of inflammatory mediators
Damaged tissue release bradykinin, potassium, histamine,
serotonin and arachidonic acid.
Arachidonic acid produce prostaglandins and leukotrienes.
43. TRANSMISSON
Process by which peripheral nociceptive information is
relayed to CNS.
First order neuron synapses with the secondary order neuron
from where impulse is carried to higher structures of brain.
Repeated or intense C fibre activation brings specific changes
on N-methyl-D-aspartate receptors resulting in central
sensitization, thus, response of second order neurons increases
as well as size of the receptive field also increases.
44. MODULATION
It is the mechanism by which transmission of impulse to the brain is
either inhibited or excitated.
Endogenous opioid peptides are naturally occurring paindampening
neurotransmitters and neuromodulators employed in suppression and
modulation of pain because they are present in large quantities in areas
of brain associated with these activities.
PERCEPTION
It is the subjective experience of pain. It is the sum of complex activities
in CNS that may shape the character and intensity of pain perceived and
ascribe meaning to pain.
45.
46. PAIN THEORIES
Pain theories are proposed to offer the possible physiologic
mechanisms involved in pain. They are as follows
Specificity theory
Pattern theory
Neuro-matrix theory
Gate control theory
47. SPECIFICITY THEORY
Proposed by Johannes Muller in 1842.
According to this theory pain is a specific modality
equivalent to vision and hearing.
This theory states pain as separate modality evoked by
specific receptors(free nerve endings) that transmit
information to pain centers or regions in the forebrain
where pain is experienced.
48. PATTERN THEORY
Proposed by Goldscheider in 1894.
According to this theory pain sensation depends on Spatio-
temporal pattern of nerve impulse reaching the brain.
According to Woddell (1962) warmth, cold and pain are words
used to describe reproducible spatio temporal pattern or codes
of neural activity evoked from skin by changes in environment.
The precise pattern of nerve impulse entering the CNS will be
different for different regions, and will vary for person to person
because of normal anatomical variations.
49. NEUROMATRIX THEORY
This theory was put forward by MELZACK
This theory explains the role of brain in pain as well as the multiple
dimensions and determinants of pain.
According to this theory the brain contains a widely distributed neural
network called the body self Neuromatrix that contains somatosensory,
limbic, & Thalamocortical components
The body self Neuromatrix involves multiple input sources such as
Somatosensory inputs
Other impulses/ inputs affecting the interpretation of the situation
Various components of stress regulation systems
Intrinsic neural inhibitory modulatory circuits
50. GATE CONTROL MECHANISM
Proposed by MELZACK & WALL IN 1965.
According to this theory, the pain stimuli transmitted by
afferent pain fibres are blocked by GATE MECHANISM
located at the posterior gray horn of the spinal cord
If the gate is open pain is felt, and if the gate is closed pain
is suppressed
Impulses in A – δ & C – fibres can be blocked by
modulated by A – β activity that can selectively block
impulses from being transmitted to the transmission cells
in the spinal cord and then to CNS resulting in no pain
51. ROLE OF BRAIN IN GATE CONTROL MECHANISM
Gates in spinal cord are
open
Pain signals reach the
thalamus through lateral
spinothalamic tract
Signals are processed in
thalamus
Signal are sent to sensory
cortex & perception of
pain occurs in cortex
Signals are sent from
cortex back to spinal cord
and the gate is closed by
releasing pain relievers
such as opioid peptides
Minimizing the
severity & extent of
pain
52.
53. Tooth pulp pain
Exposure of dentinal tubules causes toothache &
other non noxious sensation.
Both Aδ & C fibers respond to stimuli in dentine
Transmission of stimuli across dentin, mediated by
movement of fluid in dentinal tubules.
Fibers terminate at medullary dorsal horn &
synapse and also at trigeminal sensory nucleus
54. From trigeminal nucleus send to thalamus & sensory
cortex.
Pulpal innervation are capable of regenerating &
reinnervating
55. Conclusion
Anxiety is determinant for pain during dental care & pain
is related to local anesthetic procedures. There are
evidences that dentists attitude are determinants for pain.
56. References
Essential of oral physiology- Robert M Bradley
Textbook of medical physiology- Guyton & Hall
Essential of medical physiology- K.Sembulingam & Prema Sembulingam.
Textbook of human physiology- S Chand
Determinants of painful experience during dental treatment- Ruth Suzanne et al
Rev.Dor 2012;13(4)
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